Most likely edge-lit.. Full-array/Direct backlighting is more expensive and are used in higher models. Backlight bleeding is a well-known LCD problem and is expected to some degree. Unless you post a pic of yours, we can't know how bad it is... If it looks like below then it's pretty bad and worth replacing.

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Most likely edge-lit.. Full-array/Direct backlighting is more expensive and are used in higher models. Backlight bleeding is a well-known LCD problem and is expected to some degree. Unless you post a pic of yours, we can't know how bad it is... If it looks like below then it's pretty bad and worth replacing.

[attachmentid=9567627]
[attachmentid=9567630]

My advice is to not go looking for issues cuz if you are like me.. Once you find a defect, it'll forever be in your face and then you can't enjoy your purchase.

However, if still want to go ahead.. Enter the settings and play around. Focus more on modifying the Movie mode to suit your tastes. For my setup, even during the day time, I have thick curtains drawn to prevent glare from the windows. So display is setup for a darker environment. You can do the same and then try to find a balance for daylight and nighttime viewing. Check your Eco Sensor and Energy Savings settings too. You can crank up the brightness levels to max.

Better take photos or a video and share here. FYI, Samsung won't simply swap panels unless there's a distinct issue that can't be classified as normal. But if they decide it's a defect, warranty claim is a breeze.

Yes, Backlight.... Movie mode is recommended as a base to start from, cuz it offers a closer reproduction to what the content creator wanted you to see on the screen. But its all a matter of personal preference.. Which is why the different modes are available to choose from in the first place. Just like the auto-motion handling thingys, some like me absolutely hate it and switch it off others love it.. So enabled or disabled is really up to you. Summarily, tweak to the best you can enjoy depending on types of media you frequently watch. Then leave as is.. If still not satisfied, you either need a better TV or better content sources. 

It's actually refers to peak brightness. Doesn't mean it output at that level constantly.

For LCD panel, you need high peak brightness (>1000nits) and wide color gamut to achieve True HDR

I believe there is like a few option that affects dimming

1. Eco Sensor - Put to Off
2. Smart LED - Put to Off

Since you've gone through the settings and can't seem to find it. Then perhaps it's a feature that comes with the panel and can't be modified. At least not in the usual way. With your fussiness, me thinks you really should have gotten a better TV.. 
Yeah, personal preference.. For me, room styles.. especially in the Living Room? Go for Flat screens. Sure curved might look more pretty on its stand. IMO, curved screens are great when used as in PC monitors style. Cuz you sit right up close and center of the display, pretty much all the time & can take full advantage of its bend.